Corrosion resistant coatings containing an amorphous phase

ABSTRACT

The disclosure relates to the forming mineralized coatings on metal surfaces and to methods of forming such coatings. The coating can include a wide range of compounds and normally at least a portion of the coating corresponds to an amorphous phase. The coating and method are particularly useful in providing a corrosion resistant coating or film upon a metallic surface. This aspect of the disclosure involves the formation of a corrosion resistant &#34;mineralized&#34; layer of tailored composition upon a metal substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of U.S. patent applicationSer. No. 08/634,215 (Attorney Docket No. EL001RH-3) now abandoned,entitled "Corrosion Resistant buffer System for Metal Products" andfiled on Apr. 18, 1996 in the names of Robert L. Heimann, et al., whichis a continuation in part of U.S. patent application Ser. No. 08/476,271filed. on Jun. 7, 1995 now abandoned, which in turn is acontinuation-in-part of U.S. patent application Ser. No. 08/327,438filed on Oct. 21, 1994, now U.S. Pat. No. 5,714,093, the disclosure ofeach of the previously identified patent applications is herebyincorporated by reference.

FIELD OF THE INVENTION

The instant invention relates to the coatings on metal containingsurfaces and to methods of forming such coatings on a suitablesubstrate. The coating can include a wide range of compounds andnormally at least a portion of the coating corresponds to an amorphousphase. The inventive coating and method arc particularly useful inproviding a corrosion resistant coating or film upon a metallic surface.This aspect of the invention involves the formation of a corrosionresistant "mineralized" layer of tailored composition upon a metalcontaining surfaces.

BACKGROUND OF THE INVENTION

The corrosion of steel and other metal containing products continues tobe a serious technical problem which has profound effects on theeconomy. Corrosion causes loss of natural resources, and deteriorateskey infrastructure such as roads and buildings. It also causes prematurereplacement of equipment and parts in industrial facilities, boats andother marine vehicles, automobiles, aircraft, among a wide range ofmetallic components.

Current industry standards for corrosion prevention center around theuse of barrier coatings, sacrificial coatings, alloys containing heavymetals such as chromium, nickel, lead, cadmium, copper, mercury, barium,among other heavy metals. The introduction of these materials into theenvironment, however, can lead to serious health consequences as well assubstantial costs to contain or separate the materials or clean upenvironmental contamination. Damage associated with corrosion,accordingly, is a continuing problem and better systems for preventingcorrosion are still needed.

A more detailed discussion of mineral containing materials can be foundin Manual of Mineralogy, by Dana, 21^(st) edition, American Society ofMetals, vol. 13, Corrosion in Structures, "Reaction Sequence inAtmospheric Corrosion of Zinc ASTM STP 1239", by W. W. Kirk et al., andPhysics and Chemistry of Mineral Surfaces, by Bradly (1996); thedisclosure of each of the aforementioned references is herebyincorporated by reference.

Conventional practices for improving protecting metal containingsurfaces and imparting improved surface characteristics to metals relyupon compositions and methods which are undesirable as being costly orenvironmentally unsound.

SUMMARY OF THE INVENTION

The instant invention solves problems associated with conventionalpractices by providing an improved method and a composition forimproving the surface characteristics of a metal containing surface.While the inventive composition is normally compatible with conventionalcompositions and methods, the inventive composition can obviate the needto employ heavy metals such as chrome and environmentally undesirablesolvents.

The present invention in a broad aspect relates to compositions andmethods for improving or modifying the surface characteristics of ametal containing surface. In one aspect, the invention involves methodsfor forming a "mineralized" layer upon the surface of a substrate. Onemethod of forming the mineralized layer comprises delivering precursorsof the mineralized layer to the surface of the metal surface via acarrier. The carrier can be a wide range of known compositions such as afilm forming composition, lubricants, gel, sealant, adhesive, paint,solvent and water-borne resins, among other conventional compositionsfor forming coatings or films upon metals. If desired, the carrier canfunction as a reservoir of precursor materials thereby permittingadditional formation of the mineralized layer, e.g., when in thepresence of a reservoir a breach in the mineralized layer can beovercome by secondary mineral formation from mineral precursors in thereservoir- a so-called self healing effect. If desired, the carrier canalso function as a reservoir of buffer materials, e.g., materials thatpassivate the pH of the metal surface, which can protect the metalsurface by providing an environment in which the metal is resistant tochemical attack. Depending upon the utility of the carrier, the carriercan be removed or remain permanently in contact with the mineralizedsurface (and at least a portion of the metal surface).

The instant invention provides an improved surface on articles bytailoring the surface chemistry and effecting a new mineralized surfacethrough chemical reaction and interaction. The mineralized surface isformed when precursors are delivered to the surface of a metal or metalcoated articles or substrates. In some cases, the carrier includesmaterials which can function to buffer the surface, as a precursor ofthe mineralized layer, alter pH, or all of these functions. Afterproviding a proper environment, precursors can interact thereby in situforming the mineralized layer upon at least a portion of the metalsurface. Depending upon the surface environment, the metal or metalcoated substrate can contribute donor ions to react and/or interact withdelivered precursors thereby forming a relatively thin mineralized layerthat is effective in altering and preferably enhance the characteristicsof the entire article, e.g., by altering and preferably enhancing thesurface characteristics of the article. Consequently, the instantinvention permits tailoring a metal containing surface to possessimproved corrosion, coating adhesion, chemical resistance, thermalresistance, mechanical abrasion, acid rain resistance, UV resistance,resistance to effects from atomic oxygen and vacuum UV, engineeredelectrical resistance, among other improved properties. As will bedescribed below in greater detail, at least a portion of the mineralizedcoating or layer normally corresponds to a novel amorphous phase.

DETAILED DESCRIPTION

The instant invention relates to compositions and methods for forming amineralized coating or film upon at least a portion of a metalcontaining surface. By "mineralized" it is meant a compositioncontaining at least one member selected from the group of oxygenatedcations and anions wherein at least a portion of the mineral correspondsto an amorphous phase, an inorganic complex oxide crystal and mixturesthereof. Normally, the amorphous phase is the predominate phasecomponent of the mineralized layer and substantially transparent tovisible light. By "metal containing surface", "substrate", or "surface"it is meant to refer to a metallic article and any metal containingsurface as well as any substrate at least partially coated with a metallayer, film or foil including a non-metallic article having a metallayer. A wide variety of substances can be employed as precursors of themineralized layer, such as one or more cations of the metals of GroupsI, II and III, and the transition metals, of the Periodic Chart of theElements and one or more of the anions selected from the groupconsisting of silicates, molybdates, phosphates, zirconates, titanates,tungstates, vandates, permanganate, pertechnetate, chromate, nitrate,carbonates, aluminates, ferrates, mixtures thereof, among others. Atleast a portion of the resulting mineralized layer having ceramicattributes comprises:

    M.sub.x M'.sub.y M".sub.z (SiO.sub.4).sub.t (Si.sub.2 O.sub.7).sub.u (OH).sub.2 (A).sub.w (A').sub.v --nH.sub.2 O

where M, M', and M" are ions of Group I, II and/or III metals, and A andA' are alternative anions to SiO₄ and where x, y, and z each can be anynumber including zero but x, y and z cannot all concurrently be zero.Analogously, t, u, v, w and x can each be any number including zero butcannot all concurrently be zero.

The mineralized layer is formed from precursors. By "precursors" it ismeant any combination of materials which interact to form themineralized layer as well as intermediate products that interact furtherto form the mineralized layer. Examples of precursors include bufferssuch as silicate buffers and carbonate buffers including sodiumhydroxide; silicates such as at least one of sodium, calcium andpotassium silicate; silica; cations supplied or delivered to the surfacesuch as at least one of zinc, molybdenium; ions supplied or delivered tothe surface such as at least one of oxygen, sulfur or chlorine from theenvironment surrounding the precursors or surface; compounds whichdecompose or react to form a precursor or intermediate thereof; mixturesthereof, among others.

The precursors of the mineralized layer are added to any suitablecarrier. Examples of suitable carriers include hydrocarbons such as atleast one member selected from the group consisting of animal,vegetable, petroleum derived and synthetic oils such as polyalphaolefin(PAO), silicone oil, phosphate esters, fluorinated oils such as KRYTOX(supplied by the DuPont Company). Further examples of suitable carrierscomprise at least one member selected from the group consisting ofthermoplastic, thermosetting, cross-linked system, mixtures thereof,among others. Specific examples of such carriers include epoxies,acrylics, polyurethanes, silicones, polyesters, alkyds, vinyls,phenolics, fluoropolymers, latexes, mixtures thereof, among others.Depending upon the process conditions, the precursor carrier may beselected from alkylated aromatics, phosphate esters,perfluoroalkylpolyethers, polyesters, olefins, chlorotrifluoroethylene,silahydrocarbons, phosphazenes, dialkylcarbonates, oligomers,polybutenes, and polyphenyl esters, as well as unsaturated polyglycols,silicones, silicate esters, cycloaliphatic hydrocarbons, and dibasicacid esters, e.g., when applying a precursor carrier to an ironcontaining surface a polyalphaolefin base oil having a kinematicviscosity in the range of about 30-1,400 centistokes at 40° C. can beemployed. Other properties to consider when choosing an appropriatepolyalphaolefin base oil are molecular weight, molecular branching,thermal stability, and hydrophobicity, depending on the application. Thepolyalphaolefin base oil can be thickened to a gel with thickeners knownto the art of grease manufacturers such as polytetrifluoroethylene orsilica. Buffer materials are also suitable as thickeners as long as theyare compatible with the base oil. Generally, low molecular weight,synthetic, hydrocarbon oils provide greater ease in designing andmanufacturing a gel with particular desired characteristics but are morecostly than less refined, high molecular weight, petroleum hydrocarbonoils. Less refined hydrocarbons may also have the disadvantage ofcontaining sulfide compounds which can feed sulfate reducing bacteriaand, in turn, tend to corrode metals such as steel, iron and ironalloys.

The carrier film or layer can have a thickness of about 1 to at leastabout 50 mils, and typically has a thickness of about 1 to about 1.5mil, e.g., about 0.2 to at least 0.4 mil. Normally, the carrier issemipermeable thereby permitting anions from the surrounding environmentto contact precursors to the mineralized product. By "semipermeable" itis meant to refer to a microporous structure, either natural orsynthetic allowing passage of ions, water and other solvent molecules,and very small other molecules. The resin can be essentially insolublein water and resistant to macro-penetration by flowing water. The resinlayers, however, are nonnally permeable to water molecules and inorganicions such as metal ions and silicate ions.

The amount of mineralized layer precursor present in the carriertypically comprises about 1 to about 60 wt. % of the carrier, e.g,normally about 5 to about 10 wt.% depending upon the carrier. Themineralized layer precursors can be combined with the carrier in anysuitable conventional manner known in this art.

The mineralized layer precursors can include or be employed along withone or more additives such as the pH buffers such as those listed belowin Tables A and B, mixtures thereof, among others. In some cases, abuffer also functions as a precursor, e.g., sodium silicate. The amountof these additives typically ranges from about 1 to about 60 wt. % ofthe carrier, e.g., normally about 5 to about 10 wt. %. These additivescan be added to the carrier in order to tailor the characteristics ofthe mineralized layer, the carrier itself, upon a pre-treated surface,among other characteristics. By adding suitable mineralized layerprecursors, carrier, additives, among other materials, the surface ofthe metal containing layer can be tailored by forming a mineralizedlayer to possess improved corrosion resistance, adhesion, among othercharacteristics.

                  TABLE A    ______________________________________    Examples of Buffering Compounds    Chemical Name      Formula    ______________________________________    Boric Acid         H.sub.3 BO.sub.3    Citric Acid        H.sub.3 C.sub.6 H.sub.5 O.sub.7 ·H.sub.2 O    Sodium Hydroxide   NaOH    Trisodium Phosphate                       Na.sub.3 PO.sub.4 ·12H.sub.2 O    Dodecahydrate    Potassium Silicate SiO.sub.2 /K.sub.2 O 1.6-2.5 wt. ratio    Sodium Silicate    SiO.sub.2 /Na.sub.2 O 2.0-3.22 wt. ratio    Potassium Hydrogen KHC.sub.8 O.sub.4 H.sub.4    Phthalate    Potassium Dihydrogen                       KH.sub.2 PO.sub.4    Phosphate    Borax              Na.sub.2 B.sub.4 O.sub.7    Sodium Hydrogen Carbonate                       NaHCO.sub.3    Disodium Phosphate Na.sub.2 HPO.sub.4 ·12H.sub.2 O    Dodecahydrate    Sodium Acetate     NaOOCCH.sub.3    Disodium Phosphate Na.sub.2 HPO.sub.4    ______________________________________

                  TABLE B    ______________________________________    Examples of Weight Ratios of Buffering    Components for Various pH Values    De-    sired    pH   Weight  Chemical Weight                                Chemical                                       Weight Chemical    ______________________________________    3.0  1.00    Boric    0.84  Citric 0.18   Trisodium                 Acid           Acid          Phosphate    3.5  1.00    Boric    0.84  Citric  .027  Trisodium                 Acid           Acid          Phosphate    4.0  1.00    Sodium   196.00                                Potassium                                       Hydrogen                                              Phthalate                 Hydroxide    4.5  1.00    Sodium   29.30 Potassium                                       Hydrogen                                              Phthalate                 Hydroxide    5.0  1.00    Sodium   11.30 Potassium                                       Hydrogen                                              Phthalate                 Hydroxide    5.5  1.00    Sodium   6.97  Potassium                                       Hydrogen                                              Phthalate                 Hydroxide    6.0  1.00    Sodium   30.40 Potassium                                       Di-    Phosphate                 Hydroxide             hydrogen    6.5  1.00    Sodium   12.20 Potassium                                       Di-    Phosphate                 Hydroxide             hydrogen    7.0  1.00    Sodium   5.84  Potassium                                       Di-    Phosphate                 Hydroxide             hydrogen    7.5  1.00    Sodium   4.14  Potassium                                       Di-    Phosphate                 Hydroxide             hydrogen    8.0  1.00    Sodium   3.64  Potassium                                       Di-    Phosphate                 Hydroxide             hydrogen    8.5  1.00    Boric    0.84  Citric 4.80   Trisodium                 Acid           Acid          Phosphate                                              (12 H.sub.2 O)    9.0  1.00    Boric    0.84  Citric 5.82   Trisodium                 Acid           Acid          Phosphate                                              (12 H.sub. O)    9.5  1.00    Sodium   13.55 Borax                 Hydroxide    10.0 1.00    Sodium   6.52  Borax                 Hydroxide    10.5 1.00    Sodium   5.25  Borax                 Hydroxide    11.0 1.00    Sodium   2.31  Sodium Hydrogen                                              Carbonate                 Hydroxide    11.5 1.00    Sodium   8.00  Disodium                                       Acid Phosphate                 Hydroxide             (12H.sub.2 O)    12.0 1.00    Sodium   1.30  Disodium                                       Acid Phosphate                 Hydroxide             (12H.sub.2 O)    12.5 1.00    Sodium   15.00 Disodium                                       Acid Phosphate                 Hydroxide    13.0 1.00    Sodium   1.00  Sodium Acetate                 Hydroxide    ______________________________________

The aforementioned carrier can be applied to a metal containing surfaceby using any expedient method. Depending upon the desired results, themetal containing surface can be applied or reapplied as appropriate.Examples of suitable methods for applying the tailored carrier compriseat least one of painting, spraying, dipping, troweling, among otherconventional methods.

By employing a suitable tailored carrier, the instant invention can forma mineralized layer to protect a metal containing surface having atleast one member from the group of magnesium, aluminum, vanadium,calcium, beryllium, manganese, cobalt, nickel, copper, lead, copper,brass, bronze, zirconium, thallium, chromium, iron, steel, titanium,thallium, zinc, alloys thereof, among others. Particularly, desirableresults can be obtained when forming a mineralized layer upon a zinccontaining surface.

Without wishing to be bound by any theory or explanation., it isbelieved that the mineralized layer is formed under a variety ofchemical and physical forces including 1) transporting ions through thecarrier via osmotic pressure and diffusion thereby providing ions to themetal surface, 2) oxygen deprived environment, 3) buffering to provide apredetermined alkaline pH environment that is effective for formation ofthe mineralized layer upon a given metal surface, e.g, in the case of azinc containing surface about 9.5 to at least about 10.5 pH, 4)heterogeneous process using any available ions, 5) water present at thesurface, in the carrier or as a reaction product can be removed viaheat, vacuum or solvent extraction, 6) using a reservoir adjacent to themetal surface that can control that ion transport rate as well as therate of water (and moieties) passing through the reservoir and serve toprovide, as needed, a continuous supply mineralized layer precursors,among other forces.

The process for forming the inventive mineralized layer can be initiatedby delivering buffering ions of combinations or single component alkalimetal polyoxylates (for example sodium silicate) to passivate the metalsurface, e.g., refer to item 3) in the previous paragraph. In the caseof sodium silicate, the carrier contains dissolved silica in the form ofa silicate anion in water as well as sodium oxide in the form of sodiumhydroxide in the presence of water. If desired, sodium hydroxide can beemployed for maintaining the pH of the solution in a range where thesilicate can remain soluble. In the case of other substrates and otheranion systems, the buffering capacity of the reactants is designed topassivate the surface, manage the pH of the surface chemistry, and toprepare or condition the surface for a mineral-forming reaction. Thedelivery of ions is through a carrier comprising a membrane employingosmotic pressure to drive precursors to the surface.

The ionic species, which are present in the carrier or that pass throughthe carrier/membrane, can then interact chemically and can becomeassociated with the surface of the metal to form a submicronmineralization layer, e.g., a monolayer. In the present invention theseinteractions occur adjacent to or upon the surface of the substrate toform a mineralized layer. It is to be understood that the aforementionedmembrane is associated with creating an oxygen-limited passivationenvironment as part of the mineralization process.

Moreover, the mineralized layer precursors can interact in such a mannerto produce mineralized layer in-situ at the surface. Depending upon theconditions of the surface, the substrate may contribute precursors inthe form of metal ions. The metal ions of the substrate surface mayexist as oxides, or the ions may have reacted with chemical species inthe surrounding environment to form other metal species. In the case ofa zinc substrate or surface, zinc can oxidize in the environmentexisting at the surface as zinc oxide, but may also form zinc carbonatefrom the exposure to carbon dioxide in the air. Under certainconditions, the zinc carbonate will predominate the surface species ofthe precursor to form the mineralized surface. In the case of othermetal substrates, the ability of the surface to contribute ions tofunction as mineral precursors can be achieved by conditioning thesurface, e.g., to populate the surface with oxide species that willparticipate as mineralized layer precursors. Examples of surfacepreparation or surface conditioning include employing an anodic oroxidizing agent such as peroxide or sodium bicarbonate, mixtures ofagents, among others.

Depending upon the carrier and process condition, precursors can passthrough the carrier membrane system as anions, and interact adjacent toor upon the surface with metal cations, which in most cases are donatedby the metal surface or substrate to form a relatively thin mineralizedlayer, e.g., a monolayer. In one aspect of the invention, sodiumsilicate (as SiO3--ion) reacts with a zinc containing surface, e.g.,that exists primarily as zinc carbonate, to form an amorphousmineralization layer containing a nanocrystaline hemimorphite phase thatis normally less than 100 Angstroms in thickness. In this aspect of theinvention, the metal surface was prepared for mineralization by thepresence of a suitable buffering alkali, e.g., buffering with a silicateto a pH in the range of about 9.5 to about 10.5. While a higher pH canbe effectively used, a pH of less than about 11 minimizes the need forcertain relatively complex and expensive handling procedures.

In another aspect of the invention, the delivery of pH buffering agentsas well as the anion reactants can be designed to tailor the surfacecharacteristic. For example, in order to achieve improved resistance toacid rain on a zinc surface, the silicate anions can be complementedwith zirconate anions. Further, in the case of an iron containingsurface, the carrier can deliver silicate anions to a anodicallyconditioned surface to form amorphous phase comprising julgoldite.

While any suitable buffer can be employed for practicing the invention,buffer solutions are typically prepared by mixing a weak acid and itssalt or a weak base and its salt. Acidic buffers, for example, can beprepared using potassium chloride or potassium hydrogen phthalate withhydrochloric acid of appropriate concentrations. Neutral buffers can beprepared by mixing potassium dihydrogen phosphate and sodium hydroxide,for example. Alkaline (basic) buffers can be prepared by mixing borax ordisodium hydrogen phosphate with sodium hydroxide, for example. Manymore chemical combinations are possible, using appropriate chemicals toestablish the proper sequence of proton transfer steps coupled with theintended reactions. Buffer exchange rates may be modified bycombinations of buffer materials that react at different ionic exchangerates; buffers of low-change type react more rapidly than high-changetypes.

Aqueous polymers are preferred carriers for buffers in liquid form andincludes water-reducible alkyds and modified alkyds, acrylic latexes,acrylic epoxy hybrids, water reducible epoxies, polyurethanedispersions, vinyls and ethylene vinyl acetates, and mixtures thereof.Such polymers are water vapor permeable but are repellent of liquidwater and are essentially water insoluble after curing. These polymerscan form a semipermeable membrane for water vapor and ionic transfer.Hence, if the surface of the metal substrate is dry, water vapor canpermeate the membrane; but, buffering ions, which are present in themembrane or that pass through the membrane, can passivate the metalsurface thereby reducing corrosion.

Buffer materials are chosen based on the type of the surface orsubstrate to be protected. Metal substrates may be protected fromcorrosion by passivating the substrate surface. Such passivation maygenerally be accomplished only in certain pH ranges which, in turn,depend on the specific substrate to be protected. For example, ironbased alloys are passivated with an alkaline pH (pH 8-12). This pH rangeis preferably accomplished with sodium silicate and/or potassiumsilicate powders; but other alkaline materials may be used. A blend ofsodium and potassium silicates is also useful for achieving viscositycontrol in aqueous carrier/membrane formulations.

In a further aspect of the invention, a mineralized layer is obtained bymixing silicates and anodic oxidizing materials such as sodium carbonateand delivering the mixture in a manner effective to activate the metalsurface.

While the above description emphasizes a zinc containing surface, thesurface of a wide range of metal surfaces can be altered to impartbeneficial surface characteristics. In most cases, the substrate or thesurface thereof contributes cations to the mineralization-formingreaction. Examples of metal surfaces include zinc, iron, copper, brass,iron, steel, stainless steel, lead, alloys thereof, among others. In thecase of limited mineral layer formation or thickness of the minerallayer is caused by the surface contribution of the cation, an improvedresult can be obtained by managing or tailoring the pH. That is, thebuffering capacity and the pH of the carrier is substratesurface-specific and is tailored to manage the surface chemistry to formthe inventive mineralization layer, e.g., selecting a pH at which thesurface is reactive encourages formation of the mineralization layer.The reaction for forming the new surface with continue until such timethat the finite quantity of metal atoms at the surface are consumed. Ifthe new mineralized layer is marred or destroyed, a desirable aspect ofthe instant invention is that the surface will reinitiate mineralizationformation with any available precursors. The ability to reinitiatemineralization or self-repair damaged surfaces is a novel andparticularly desirable characteristic of the invention.

The delivery/method of the alkali metal polyoxolates (or mineralizationlayer) can be provided through a membrane from a reservoir as describedin the U.S. patent application Ser. No. 08/634,215; previouslyincorporated by reference. In the present invention, soluble precursors,such as silicate materials, are used within one or more coating layers.For example, in a polymer containing carrier system, one of the layerswould be charged with sodium or potassium silicates wherein the outerlayer(s) are employed to control the rate of moisture flow through thecarrier. These carriers are typically relatively hard films as thenormal polymerization of the carrier occurs to form a plastic typepolymer type coating. Additional delivery methods have been developedutilizing soft films, gels, sealants, adhesives, and paints wherein themembrane feature is formed in-situ by the reaction between a silicate,e.g., sodium silicate, and silica. By controlling the quantity of thesilica in the carrier, the mineralized layer can be designed to suit thespecific application. Depending upon the pH and relative concentrationof silicate and silica, the degree of crystal formation, e.g., a silicacontaining hemimorphite within an amorphous layer, can also be designedto achieve a predetermined result.

Without wishing to be bound by any theory or explanation the formationof the mineralized layer can occur under a wide range of conditions(normally ambient) and via a plurality of mechanisms. Normally, themineralization layer forms underneath the carrier upon the metalsurface, e.g., as buried layer under a carrier comprising a reservoir ofprecursors. If so formed, whatever ions are needed in the reservoirlayer to form the mineralized layer, are expediently included as watersoluble salts in the reservoir layer. On the other hand, all the ionsemployed to form the mineralized layer need not necessarily be includedin the reservoir layer. That is, if desired cations can be supplied fromthe underlying metal surface and need not necessarily be included aswater soluble salts in the reservoir layer. Such cations can be obtainedfrom the surface of the substrate metal itself, by reaction of thesubstrate with the anions of the precursor component for the mineralizedlayer. Since the mineralized layer is normally relatively thin,sufficient cations for the mineralized layer can even be supplied fromthe substrate when present only as an alloying ingredient, or perhapseven as an impurity. Additionally, the cations needed for themineralized layer can be supplied from water soluble salts in thereservoir layer, as indicated above. Further, if the mineralized layeris to be formed from an overlying reservoir layer that also containsbuffer components, at least some to the salts used for buffering can beemployed for forming the mineralized layer. The latter reservoir layerwould possess a self healing effect by functioning as a source ofminerization precursors in the event the layer was damaged. Once themineralization layer has been formed to the degree desired, the carrieror reservoir layer can remain as a component of the finished article orremoved.

Applications for the films and coatings of the invention include, forexample, components such as coatings and paints of components, parts andpanels for use the automotive industry, home-consumer products,construction and infrastructures, aerospace industry, and other out-dooror corrosive applications wherein it is desirable to improve thecharacteristics of a metal surface and the use of heavy metals inelemental or non-elemental form is environmentally undesirable. Thefilms and coatings may be applied to new products or over conventionalplatings to extend the useful service life of the plated component.

While the above description places particular emphasis upon forming asilicate containing mineralized layer, one or more mineralized layershaving chemically similar or distinct compositions can be applied uponthe same metal surface. If desired, the mineralized surface can befurther modified by using conventional physical or chemical treatmentmethods.

The following Examples are provided to illustrate not limit the scope ofthe invention as defined in the appended claims. These Examples containresults of the following analysis: Auger Electron Spectroscopy (AES),Electronic Impedance Spectroscopy (EIS), and X-ray PhotoelectronSpectroscopy (XPS). These analysis were performed using conventionaltesting procedures. The results of the AES demonstrate that thethickness of the mineralized layer can range from about 10 to 50microns. EIS demonstrates that the mineralized layer imparts corrosionresistant properties to the surface, e.g., a reduced Icorr correspondsto a reduced corrosion current and in turn a reduced corrosion rate. TheXPS data demonstrates the presence of a unique hemimorphite crystalwithin the mineralized layer, e.g., XPS measures the bond energy betweensilicon and oxygen atoms and compares the measured energy tostandardized values in order to determine whether or not known crystalsare present. Conventional X-ray diffraction analysis confirmed that themineralized layer is predominately amorphous, e.g., an X-ray measurementresulted in wide bands thereby indicating the presence of an amorphousphase.

EXAMPLES Auger Electron Spectroscopy

Examples 1-4 were prepared and analyzed in accordance with the followingAES procedure.

Instrumentation Used

Instrument: Physical Electronics 545, Single Pass Cylindrical Analyzer

Sample Excitation:

Electron Gun

Emission Current, 1 mA

Beam Voltage, 3 kV

Electron Beam Detection: Multiplier Voltage, 1 kV

Modulation Voltage, 3 eV

Signal Detection: Lock-in Magnification, 10X

Lock-in Time Constant, 0.001 sec.

Sputter Gun Settings: Beam Voltage, 3 kV

Focus Dial Setting, 2

Raster X Dial Setting, 10

Raster Y Dial Setting, 10

Emission Current, 15, mA

Sputter Rate, 12 Å/min

Start Time, 0 min.

Final Time, 30 min

Sputter Depth, 360 Å

Example 1

The coating had a first layer with the following formulation (byweight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

and a second layer with the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The components were mixed by hand for approximately 15 minutes. Thefirst layer was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, with a dry film thickness of about0.5 to 0.7 mil. This layer was dried to tack free at 60 C for 10minutes. The second layer was then applied, with a dry film thickness ofabout 0.5 to 0.7 mil. This layer was also dried to tack free at 60 C for10 minutes. The second layer was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX. Stripper (WalmartStores) and a plastic spatula. The residual coating was washed off withcopious amounts of Naptha (Commercial Grade, Walmart Stores), andReagent Alcohol (Fisher Scientific).

Example 2

The coating had one layer with the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

and a second layer with the following formulation (by weight)

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The components were mixed by hand for approximately 15 minutes. Thefirst layer was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, with a dry film thickness of about0.5 to 0.7 mil. This layer was dried to tack free at 60 C. for 10minutes. The second layer was then applied, with a dry film thickness ofabout 0.5 to 0.7 mil. This layer was also dried to tack free at 60 C.for 10 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual coating was washed off withcopious amounts of Naptha (Commercial Grade, Walmart Stores), andReagent Alcohol (Fisher Scientific).

Example 3

The coating had one layer with the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

and a second layer with the following formulation (by weight)

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The components were mixed by hand for approximately 15 minutes. Thefirst layer was then cast onto a standard zinc phosphated, 1010 steeltest panel, obtained through ACT Laboratories, with a dry film thicknessof about 0.5 to 0.7 mil. This layer was dried to tack free at 60 C. for10 minutes. The second layer was then applied, with a dry film thicknessof about 0.5 to 0.7 mil. This layer was also dried to tack free at 60 C.for 10 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual was washed off with copiousamounts of Naptha (Commercial Grade, Walmart Stores), and ReagentAlcohol (Fisher Scientific).

Example 4

The coating had one layer with the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

and a second layer with the following formulation (by weight)

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The components were mixed by hand for approximately 15 minutes. Thefirst layer was then cast onto a standard iron phosphated, 1010 steeltest panel, obtained through ACT Laboratories, with a dry film thicknessof about 0.5 to 0.7 mil. This layer was dried to tack free at 60 C. for10 minutes. The second layer was then applied, with a dry film thicknessof about 0.5 to 0.7 mil. This layer was also dried to tack free at 60 C.for 10 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual was washed off with copiusamounts of Naptha (Commercial Grade, Walmart Stores), and ReagentAlcohol (Fisher Scientific).

Each of the previously described washed test panels were passed throughan AES analysis in accordance with conventional methods. This analysisconfirmed the presence of the inventive mineral layer and generated datawhich demonstrated that for each substrate, the thickness of themineralized layer was on the order of about 50 to about 70 Å thick.

Electrical Impedance Spectroscopy

Examples 5 through 13 were prepared for Electrochemical ImpedanceSpectroscopy (EIS) analysis. EIS is one method of determining corrosionrates of a metal or a coated metal. In this technique, a small-amplitudesinusoidal potential perturbation was applied to the working electrodeat a number of discrete frequencies ranging from 60,000 Hz to 0.0005 Hz.At each one of these frequencies, the resulting current waveformexhibited a sinusoidal response that was out of phase with the appliedpotential signal by a certain amount. The electrochemical impedance wasa frequency-dependent proportionality factor that acts as a transferfunction by establishing a relationship between the excitation voltagesignal and the current response of the system. This method was detailedby the American Society for Testing and Materials (ASTM) inElectrochemical Corrosion Testing, STP 727.

Example 5

A gel was prepared having the following formulation (by weight):

10% Cab-O-Sil TS-720 Silica

90% Amoco DURASYN™ 174 polyalphaolefin

The above formulation was mixed in a Hobart Mixer (model N-50) forapproximately 30 minutes. The gel was then cast onto a standardelectrogalvanized test panel, obtained through ACT Laboratories, at athickness of 1/16" to 1/8". The gel was left on the panel for a minimumof 24 hours. Most of the gel was then removed with a plastic spatula.The residual gel was washed off with copius amounts of Naptha(Commercial Grade, Walmart Stores), and Reagent Alcohol (FisherScientific).

Example 6

A gel was prepared having the following formulation (by weight):

10% Cab-O-Sil TS-720 Silica

20% G-Grade Sodium Silicate (PQ Corporation)

70% Amoco DURASYN™ 174 polyalphaolefin

The above formulation was mixed in a Hobart Mixer (model N-50) forapproximately 30 minutes. The gel was then cast onto a standardelectrogalvanized test panel, obtained through ACT Laboratories, at athickness of 1/16" to 1/8". The gel was left on the panel for a minimumof 24 hours. Most of the gel was then removed with a plastic spatula.The residual was washed off with copius amounts of Naptha (CommercialGrade, Walmart Stores), and Reagent Alcohol (Fisher Scientific).

Example 7

A gel was prepared having the following formulation (by weight):

10% Cab-O-Sil TS-720 Silica

20% Sodium Molybdate (Fisher Scientific)

70% Amoco DURASYN™ 174 polyalphaolefin

The above formulation was mixed in a Hobart Mixer (model N-50) forapproximately 30 minutes. The gel was then cast onto a standardelectrogalvanized test panel, obtained through ACT Laboratories, at athickness of 1/16" to 1/8". The gel was left on the panel for a minimumof 24 hours. Most of the gel was then removed with a plastic spatula.The residual was washed off with copius amounts of Naptha (CommercialGrade, Walmart Stores), and Reagent Alcohol (Fisher Scientific).

Example 8

A gel was prepared having the following formulation (by weight):

10% Cab-O-Sil TS-720 Silica

20% Sodium Phosphate (Fisher Scientific)

70% Amoco DURASYN™ 174 polyalphaolefin

The above formulation was mixed in a Hobart Mixer (model N-50) forapproximately 30 minutes. The gel was then cast onto a standardelectrogalvanized test panel, obtained through ACT Laboratories, at athickness of 1/16" to 1/8". The gel was left on the panel for a minimumof 24 hours. Most of the gel was then removed with a plastic spatula.The residual was washed off with copius amounts of Naptha (CommercialGrade, Walmart Stores), and Reagent Alcohol (Fisher Scientific).

This Example was repeated with the exception that sodium carbonate wasemployed instead of sodium phosphate.

Example 9

A coating was prepared having the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, at a thickness for a total dry filmthickness of 2.1 to 2.5 mils in three layers. Each layer was dried totack free at 60 C. for 15 minutes. The coating was left on the panel fora minimum of 24 hours. Most of the coating was then removed with BIXStripper (Walmart Stores) and a plastic spatula. The residual was washedoff with copius amounts of Naptha (Commercial Grade, Walmart Stores),and Reagent Alcohol (Fisher Scientific).

Example 10

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, at a thickness for a total dry filmthickness of 2.1 to 2.5 mils in three layers. Each layer was dried totack free at 60 C. for 15 minutes. The coating was left on the panel fora minimum of 24 hours. Most of the coating was then removed with BIXStripper (Walmart Stores) and a plastic spatula. The residual was washedoff with copius amounts of Naptha (Commercial Grade, Walmart Stores),and Reagent Alcohol (Fisher Scientific).

Example 11

A coating was prepared having the following formulation (by weight):

6.5% Sodium Vanadate Solution (156.3 grams/liter)

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, at a thickness for a total dry filmthickness of 2.1 to 2.5 mils in three layers. Each layer was dried totack free at 60 C. for 15 minutes. The coating was left on the panel fora minimum of 24 hours. Most of the coating was then removed with BIXStripper (Walmart Stores) and a plastic spatula. The residual was washedoff with copius amounts of Naptha (Commercial Grade, Walmart Stores),and Reagent Alcohol (Fisher Scientific).

Example 12

A coating was prepared having the following formulation (by weight):

6.5% Sodium Molybdate Solution (274.21 grams/ liter)

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, at a thickness for a total dry filmthickness of 2.1 to 2.5 mils in three layers. Each coat was dried totack free at 60 C. for 15 minutes. The coating was left on the panel fora minimum of 24 hours. Most of the coating was then removed with BIXStripper (Walmart Stores) and a plastic spatula. The residual was washedoff with copius amounts of Naptha (Commercial Grade, Walmart Stores),and Reagent Alcohol (Fisher Scientific).

Example 13

A coating was prepared having the following formulation (by weight):

6.5% Sodium Carbonate Solution (120.12 grams/ liter)

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard 1010 steel test panel,obtained through ACT Laboratories, at a thickness for a total dry filmthickness of 2.1 to 2.5 mils in three layers. Each layer was dried totack free at 60 C. for 15 minutes. The coating was left on the panel fora minimum of 24 hours. Most of the coating was then removed with BIXStripper (Walmart Stores) and a plastic spatula. The residual was washedoff with copius amounts of Naptha (Commercial Grade, Walmart Stores),and Reagent Alcohol (Fisher Scientific).

The cleaned samples from Examples 5 to 13 were then tested by EIS inaccordance with the following method.

Instrument: Solartron 1287 Electrochemical Interface

Solartron 1260 Impedance/Gain-Phase Analyzer

ZW are and CorrWarr Software by Scribner

Settings: 60,000 to 0.005 Hz.

10 steps/decade

5 mV rms AC. signal

Test Solution: 1 Molar Ammonium Sulfate, pH=3.0 (using 0.1N SulfuricAcid) for electrogalvanized substrates.

1 Molar Ammonium Sulfate, pH=2.0 (using 0.1N Sulfuric Acid) for 1010Steel substrates.

B value: corresponds to the average of the Tafel slope B=(BcBa)/(Bc+Ba)

icorr: corresponds to the current generated by corrosion

The following Table sets forth the results of the EIS Procedure for thezinc substrate in Examples

    ______________________________________    EIS TABLE FOR ZINC SUBSTRATES           B         i.sub.corr     ave. i.sub.corr                                          EXPL  Com-    surface           (mV)      μA/cm.sup.2                             ave. B μA/cm.sup.2                                          NO.   ments    ______________________________________    Bare Zinc           0.062632  193.3   0.067255                                    205.5 standard           0.060229  204.4                std           0.063586  226.3                std           0.101038  85.3                 std   .sup. 1           0.071548  213.1                std            0.0792307                     243.6                std   .sup.11           0.078282  190.2                std    Gel    0.054997  120.4   0.055658                                    130.1 5           0.045513  148.5                5           0.035642  64.8                 5           0.041034  79.7                 5           0.039146  72.5                 5           0.060190  113.1                5           0.061932  138.5                5    Na.sub.2 SiO.sub.4           0.072070  110.7   0.047529                                    97.5  6           0.059899  121.5                6           0.035932  93.2                 6           0.038235  107.7                6           0.040076  67.3                 6           0.038964  84.7                 6    Na.sub.2 MoO.sub.4           0.052667  99.3    0.061923                                    128.5 7           0.072482  191.1                7           0.059900  98.5                 7           0.065942  128.6                7           0.058622  125.0                7           0.090991  153.9                7     .sup.2    Na.sub.2 PO.sub.4           0.047173  93.3    0.049479                                    153.9 8           0.045828  141.0                8           0.053326  232.8                8           0.056754  178.1                8           0.058574  194.0                8           0.035220  84.2                 8    Na.sub.2 CO.sub.3           0.041397  68.4    0.047339                                    98.7  8           0.044320  121.8                8     .sup.2           0.046295  81.1                 8           0.057343  123.4                8     .sup.3    ______________________________________     .sup.1 Cell leaked at the base, setting up a localized galvanic cell.     .sup.1 Cell leaked underneath gasket.     .sup.2 Cell leaked at the base, discarded this data point.

The results of the EIS indicates that the greatest corrosion resistance(low icorr) for a zinc substrate is obtained by a sodium silicate orsodium silicate or sodium carbonate mineral layers.

The following Tables list the corrosion data for the steel surfaces ofExamples 9-13.

    ______________________________________             Hours     B       R.sub.p i.sub.corr    surface  Immersed  (mV)    (ohm-cm.sup.2)                                       (μA/cm.sup.2)    ______________________________________    Coating Without Silicates-Example 9    steel    24        39.4    68      580    --       49        33.8    55      614    --       74        33.8    116      290, pH = 2.86    --       99        33.8    25      1352, pH = 2.0    --       21        34.4    54      637    --       44        36.3    95.8    379    --       68        45      55.6     808, pH = 2.36    --       1         46.1    59.3    777    --       24        41.7    43.8    952    --       48        43.3    55.5    780, pH = 2.4    --       1         42      135     311    --       24.5      40.8    51.8    788    --       48        40.5    53      764, pH = 2.5    Coating Containing Sodium Silicate-Example 10    steel    24        30.3    47.5    640    --       49        35.3    55      642    --       74        35.3    267      132, pH = 3.15    --       99        35.3    20      1765, pH = 2    --       1.5       43.4    74.4    584    --       21        35.5    94.2    377    --       44        31.5    125     252    --       68        33.8    172      196, pH = 2.25    steel - coating             1         36.7    564      65    was not    completely    stripped    steel    26        33.2    371      90    --       57        33.2    554      60    steel - coating             1         42.4    32.6    1300    was restripped    steel    1         42.2    59.7    707    --       24        40.8    58.7    695    --       48        40.8    70.2    581, pH = 2    Coating Containing Sodium Vandate-Example 11    steel    25        305.8   55.5    645    --       49        33.9    75.8    448    --       74        33.9    82.6    410, pH = 2.8    --       78        42.2    25.7    1640, pH = 2    --       1.5       50.5    70      721    --       21        36.5    92      397    --       44        33.3    126     265    --       68        33.2    161      206, pH = 2.25    --       1         40.8    146     280    --       24        40.6    64.6    632    --       48        40.6    75.6    537, pH = 2    --       1         42.6    62.9    677    --       24        34.6    65      536    --       48        39.1    110     355, pH = 2.1    Coating Containing Sodium Molybdate-Example 12    steel    21        37.4    51.3    729    --       44        44.4    45.6    973    --       68        41.4    54.3     763, pH = 2.35    steel - coating             1         37.7    190     198    was not    completely    removed    steel    26        36.6    138     265    --       57        36.6    212     173    steel - coating             1         33.3    112     353    was not    completely    removed)    --       24        40.4    96.6    409    --       48        39.5    130     293, pH = 2.2    --       1         46.9    42.5    1109    --       24        48.2    28.6    1687    --       44        46      45.2    1018, pH = 2.15    Coating Containing Sodium Carbonate-Example 13    steel    25        37.2    82.5    451    --       49        27.6    123.5   223    --       74        27.6    128.8   214, pH = 2.3    --       78        37.2    34.4    1080, pH = 2    --       1         41.8    56.8    735    --       24.5      44.2    33.5    1320    --       48        43.4    40.7    1066, pH = 2.9    --       1         39.5    112     353    --       24        40.6    96.6    409    --       48        38.1    130     293, pH = 2.2    --       1         45.7    46.7    978    --       24        46.5    29.7    1566    --       44        44.4    41.4    1072, pH = 2.15    ______________________________________     Based upon the measured corrosion currents, sodium carbonate and sodium     silicate are

Based upon the measured corrosion currents, sodium carbonate and sodiumsilicate are

the most effective in reducing the icorr thereby indicating a reducedcorrosion rate.

X-Ray Photoelectron Spectroscopy (XPS)

X-ray Photoelectron Spectroscopy (XPS) was performed on a series ofsamples in Examples 14-24 that included 1010 Steel and ElectrogalvanizedSteel. XPS was performed in accordance with conventional procedures inthis art.

Instrumentation Used

Instrument: Physical Electronics 5701 LSci

X-ray Source: Monochromatic aluminum

Source Power: 350 watts

Analysis Region: 2 mm×0.8 mm

Exit angle: 65°

Acceptance angle: ±7°

Charge reference: B.E. of C-)H,C)=284.6 eV

Charge neutralization: flood gun

Sampling Depth: (3λ) was 70 Å

Example 14

A coating was prepared having the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual was washed off with copiusamounts of Naptha (Commercial Grade, Walmart Stores), and ReagentAlcohol (Fisher Scientific).

Example 15

A coating was prepared having the following formulation (by weight):

25% Water (Fisher Scientific)

75% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coated panel was then exposed to a post-cure heattreatment of 1 hour at 125° C., using a standard laboratory oven. Thecoating was left on the panel for a minimum of 24 hours. Most of thecoating was then removed with BIX Stripper (Walmart Stores) and aplastic spatula. The residual was washed off with copius amounts ofNaptha (Commercial Grade, Walmart Stores), and Reagent Alcohol (FisherScientific).

Example 16

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual was washed off with copiusamounts of Naptha (Commercial Grade, Walmart Stores), and ReagentAlcohol (Fisher Scientific).

Example 17

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coating was left on the panel for a minimum of 24hours. Most of the coating was then removed with BIX Stripper (WalmartStores) and a plastic spatula. The residual was washed off with copiusamounts of Naptha (Commercial Grade, Walmart Stores), and ReagentAlcohol (Fisher Scientific).

Example 18

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coated panel was then exposed to a post-cure heattreatment of 125° C. for one hour, in a standard laboratory oven. Thecoating was left on the panel for a minimum of 24 hours. Most of thecoating was then removed with BIX Stripper (Walmart Stores) and aplastic spatula. The residual was washed off with copius amounts ofNaptha (Commercial Grade, Walmart Stores), and Reagent Alcohol (FisherScientific).

Example 19

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The above formulation was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three layers. Each layer was dried to tack free at 60 C.for 15 minutes. The coated panel was then exposed to a post-cure heattreatment of 175° C. for one hour, in a standard laboratory oven. Thecoating was left on the panel for a minimum of 24 hours. Most of thecoating was then removed with BIX Stripper (Walmart Stores) and aplastic spatula. The residual was washed off with copius amounts ofNaptha (Commercial Grade, Walmart Stores), and Reagent Alcohol (FisherScientific).

Example 20

For purposes of comparing the results achieved by Examples 14-19, anelectrogalvanized panel was soaked for 24 hours in a solution that hadthe following formulation (by weight):

25 mg/l Sodium Silicate

The sample panel was allowed to air dry.

Example 21

For purposes of comparing the results achieved by Examples 14-19, anelectrogalvanized panel was soaked for 24 hours in a solution that hadthe following formulation (by weight):

25 mg/l Sodium Silicate

The sample panel was allowed to air dry. The panel was then exposed to apost-dry heat treatment of 125° C. for one hour, in a standardlaboratory oven.

Example 22

For purposes of comparing the results achieved by Examples 14-19, anelectrogalvanized panel was soaked for 24 hours in a solution that hadthe following formulation (by weight):

25 mo/l Sodium Silicate

The sample panel was allowed to air dry. The panel was then exposed to apost-dry heat treatment of 175° C. for one hour, in a standardlaboratory oven.

Example 23

A crystal sample of Zn₂ SiO₄, which was air fractured and immediatelyintroduced into the sample chamber of the XPS. The total air exposurewas less than 2 minutes. The surface was examined initially with a lowresolution survey scan to determine which elements were present. Highresolution XPS spectra were taken to determine the binding energy of theelements detected in the survey scan. The quantification of the elementswas accomplished by using the atomic sensitivity factors for a PhysicalElectronics 5701 LSci ESCA spectrometer.

The following Table sets forth the silicon binding energies which weremeasured for Examples 14-23.

    ______________________________________    Example Number               Treatment     Si 2p peak Energy (eV)    ______________________________________    14         Room Temp     101.9    15         125° C.                             101.8    16         Room Temp     102.8    17         Room Temp     102.8    18         125° C.                             102.6    19         175° C.                             102.6    20         25 ppm Na.sub.2 SiO.sub.4,                             101.7               25° C.    21         25 ppm Na.sub.2 SiO.sub.4,                             101.7               125° C.    22         25 ppm Na.sub.2 SiO.sub.4,                             101.8               175° C.    23         Zn.sub.2 SiO.sub.4 crystal                             101.5    ______________________________________

The above Table illustrates that there has been a change in theconcentration of Si as well as the bond energy thereby providing furtherconfirmation of the presence of the mineralized layer. Further, theSi--O bond energy of conventional zinc silicate crystal as well as thesilicate soaked panels is distinct from the inventive mineralized layer.

Example 24

A coating was prepared having the following formulation (by weight):

6.5% N-grade Sodium Silicate

13% Water (Fisher Scientific)

80.5% NeoRezR-9637 (Zeneca Resins)

The formulation above was mixed by hand for approximately 15 minutes.The coating was then cast onto a standard electrogalvanized test panel,obtained through ACT Laboratories, for a total dry film thickness of 2.1to 2.5 mils in three coats. Each coat was dried to tack free at 60 C.for 15 minutes. The panel was exposed to ASTM B 117 Salt Fog Chamber for2400 hours. At the end of the salt fog exposure, there were large areasof the panel that were uncorroded. The area of uncorroded surface wascut into a small square sample and the urethane coating was removed byhand, using small tweezers. The sample was analyzed in accordance withthe previously identified XPS method on an instrument of comparablesensitivity and accuracy. The results of the XPS are set forth in thefollowing Table.

                  EXAMPLE 24    ______________________________________    Silicate Containing Coating Followed by Salt Spray Exposure                                  Relative Concentration of    Example             Si 2p peak                                  Silicon on the Surface    Number Treatment    Energy (eV)                                  (% wt)    ______________________________________    14     urethane coating,                        101.9     negligible at 1.0%           room temp    15     urethane coating,                        101.8     negligible at 0.8%           125° C.    16     silicate, room temp                        102.8     19.8%    17     silicate     102.8     18.9%           125° C.    18     silicate,    102.6     15.8%           room temp    19     silicate,    102.6     11.6%           175° C. (heat           applied after           coating removed)    20     immersion,   101.7      4.1%           25 ppm Na.sub.2 SiO.sub.4,           25° C.    21     immersion,   101.7      3.2%           25 ppm Na.sub.2 SiO.sub.4,           125° C.    22     immersion,   101.8      3.9%           25 ppm Na.sub.2 SiO.sub.4,           175° C.    23     Zn.sub.2 SiO.sub.4 crystal                        101.5     NA    24     silicate, room temp,                        102.6      8.1%           2400 hours of B117           exposure    ______________________________________

The above Table illustrates that the binding energy for the surfaceexposed to the silicate containing coatings range from 102.6 to 102.8.By observation of the XPS peak, it was observed that these energy valueswere actually manifold values from manifold peaks that contain more thanone material. These materials can be characterized as a disilicate, orhemimorphite (bonding energy at 102.2), altered by the presence of Si--Obonds, as in SiO2 (bonding energy at 103.3) and Si--O-C. bonds with abonding energy of 103.6 or 103.7. Such a bonding energy andconcentration of Si on the surface are distinct from conventional silicaor silicate structures. The binding energy, for zinc silicate, Zn₂SiO₄,101.5 eV, is also distinct from the binding energy of themineralized layer, 102.7 eV, or the hemimorphite.

It is to be understood that the foregoing is illustrative only and thatother means and techniques may be employed without departing from thespirit or scope of the invention as defined in the following claims.

The following is claimed:
 1. A mineralized layer comprising an amorphousphase and an inorganic complex crystalline material comprising at leastone ion selected from group consisting of Group I, II and III metals; analkali metal, silicon and oxygen within the amorphous phase, made by aprocess comprising contacting a substrate with a mineral precursorwherein said precursor interacts with at least a portion of thesubstrate to form said layer and the precursor comprises at least onemember selected from the group consisting of silicates, silica, sodiumhydroxide molybdates, phosphates, zirconates, titanates, tungstates,vandates, permanganate, pertechnetate, chromate, nitrate, carbonates,aluminates, and ferrates and wherein the precursor is dispersed within acarrier comprising at least one member selected from the groupconsisting of synthetic oil, naturally occurring oil or wax andpolymeric resin material.
 2. A mineralized layer comprising a reactionproduct formed in situ between a substrate and a precursor comprising atleast one member selected from the group consisting of silicates,silica, sodium hydroxide, molybdates, phosphates, zirconates, titanates,tungstates, vandates, permanganate, pertechnetate, chromate, nitrate,carbonates, aluminates, and ferrates and wherein the precursor isdispersed within a carrier comprising at least one member selected fromthe group consisting of synthetic oil, naturally occurring oil or waxand polymeric resin material and wherein the reaction product comprisesan amorphous phase and an inorganic complex crystalline materialcomprising at least one ion selected from the group of Group I, II andIII metals; silicon, an alkali metal and oxygen within said phase andwherein the amount of oxygen present in said inorganic complexcrystalline material is less than stoichometric.
 3. A corrosionresistant mineralized layer formed in situ between a substrate and aprecursor comprising at least one silicate and optionally at least onemember selected from the group consisting of molybdates, phosphates,zirconates, titanates, tungstates, vandates, permanganate,pertechnetate, chromate, nitrate, carbonates, aluminates, and ferratesand wherein the precursor is dispersed within a carrier comprising atleast one member selected from the group consisting of synthetic oil,naturally occurring oil or wax an polymeric resin material and whereinthe corrosion resistant mineralized layer comprises an amorphous phaseand an inorganic complex crystalline material.
 4. The mineralized layerof claim 1 2, or 3 wherein the substrate comprise at least one memberselected from the group consisting of iron, steel, zinc, magnesium,aluminum, vanadium, calcium, beryllium, manganese, cobalt, nickel,copper, zirconium, thallium, and chromium.
 5. The mineralized layer ofclaim 1 or 2 wherein the electrical impedance spectroscopy value of thelayer is less than about 121 μA/cm2.
 6. The mineralized layer of claim 1or 2 wherein the electrical impedance spectroscopy value of the layer isless than about 205 μA/cm2.
 7. The mineralized layer of claim 1 or 2wherein the Si--O bonding energy is less than about 102.8 eV.
 8. Themineralized layer of claim 1 or 2 wherein the alkali metal comprises atleast one of sodium and potassium.
 9. The mineralized layer of claim 1or 2 wherein the substrate comprises iron or an iron alloy.
 10. Themineralized layer of claim 1, 2 or 3 wherein the substrate compriseszinc.
 11. The mineralized layer of claim 1, or 2 wherein the bondingenergy for Si--O in the layer as measured by XPS is greater than thatmeasured for Zn₂ SiO4.
 12. The mineralized layer of claim 1, or 2wherein the thickness of the layer is less than 100 Angtroms.
 13. Thecorrosion resistant mineral layer of claim 3 wherein the carriercomprises at least one member selected from the group consisting ofpolyalpholefins, polyurethanes, epoxies and acrylics.
 14. The corrosionresistant mineral layer of claim 3 wherein the precursor comprises about1 to about 60 wt. % of the carrier.